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You could try to isolate the problem by trying a different browser. I find youtube videos to be of varying sound quality. My solution for fixing it is to temporarily download the video and play it in VLC or smplayer where I can apply filters and normalisation.

catweazel wrote:You could try to isolate the problem by trying a different browser. I find youtube videos to be of varying sound quality. My solution for fixing it is to temporarily download the video and play it in VLC or smplayer where I can apply filters and normalisation.

Sorry I forgot to tick "Notify me when a reply is posted".

It is definitely not a problem caused by specific videos. To describe it more detailled:

- any videos watching in fullscreen with Firefox (56.0 (64-bit)) have blurred sound
- not only youtube but other websites providing videos as well
- it is not a hardware problem because I was using the Notebook with standard Debian 7 and 8 wihtout any sound problems
- downloaded videos don't show this sound problem but downloading videos or switching the browser is not an option in long term (in this case, helping a friend)
- I remember the same problem with Linux Mint 17

Any ideas?

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